Heterogeneous catalyst components for olefins polymerization, preparation process and use thereof

ABSTRACT

It is shown metallocenes with functionalized bridge of formula  
                 
 
     wherein M represents a transition metal of groups 3, 4, 5 or 6, L represents cyclopentadieliyl-type ligands, Y represents a halogen and which can own one or various bridges between uritics L. At least one of these bridges is functionalized through a group constituted by the union between a halogen atom and a silicon, germanium or tin atom. It is also shown a method for the synthesis of these metallocene compounds starting from the corresponding metallic halure and a precursor of the ligand which has leaving groups. These metallocene compounds are used as catalyst precursors for the homopolymerization and copolymerization of olefins. It is also shown methods for supporting these metallocenes on inorganic solids in order to obtain solid catalyst systems for olefins polymerization processes in a heterogeneous phase.

STATE OF THE ART PRIOR TO THE INVENTION

[0001] It is well known that metallocene compounds such asbis(cyclopentadienyl)titanium dialkyl or bis(cyclopentadienyl)zirconiumdialkyl in combination with alkyl aluminiums act as catalysts for olefinpolymerization in homogeneous phase. Thus, German patent DE-2,608,863describes the use of bis(cyclopentadienyl)titanium dialkyl incombination with trialkylaluminium and a controlled quantity of water inolefins polymerization.

[0002] The controlled hydrolysis of alkyl aluminiums gives rise to theformation of species containing an Al—O bond (aluminoxane) which arereal co-catalysts in the polymerization of olefins with metallocenes.Kaminsky (Adv. Organomet. Chem. b 1980, 18, 99) shows that aluminoxanesin combination with dichlorometallocenes produce catalyst systems whichare very active in ethylene polymerization.

[0003] It is also possible (Turner, EP 277004 and Ewen et al. EP 426637)to use co-catalysts formed by bulky boron compounds which, acting asnon-coordinative anions, stabilize the cationic form of the metallocenewithout preventing the incorporation of the olefin in the polymerizationprocess.

[0004] The polymerization processes that use homogeneous catalystsystems produce high polymerization activities. However, most industrialprocesses require heterogenous catalyst systems which on the one handproduce polymers with a controlled morphology, but on the other handhave an activity of the order of the homogeneous systems.

[0005] In European patent EP 206794 it is described heterogeneouscatalysts obtained through simultaneous or subsequent (in any order)addition of aluminoxanie and metallocene onto an inorganic support.

[0006] This process, according to patent EP 260130, can also be appliedto multicomponent systems. These catalysts are those which containvarious metallocenes or one metallocene and one non-metallocene compoundof a transition element. In this way, polyolefins with a multimodalmolecular weight distribution are obtained.

[0007] In patents EP 361866, EP 323716, EP 367503, EP 368644 and US5057475 it is described the preparation of a heterogeneous catalystsystem composed by one aluminoxane and one metallocene characterized inthat the aluminoxane is generated “in situ” through reaction of atrialkylaluminium with undehydrated silica. The use of this catalystsystem in α-olefins polymerization gives rise to high activities.

[0008] Another well known technique used in the preparation ofheterogeneous catalysts is the chemical modification of the inorganicsupport. In patents EP 474391 and EP 314797 it is described a processwherein the support, before the addition of the metallocene, is treatedwith an organoaluminium compound which reacts with the hydroxyl groupspresent on the silica surface.

[0009] The above described catalyst systems present the drawback thatthe catalyst is not tightly enough bonded to the support so that theseparation of the metallocene from the support can occur, producingpolymerization in solution, which prejudices the morphology of theobtained polymer.

[0010] As a consequence of that, methods for obtaining the formation ofa chemical bond between the support and the metallocene are looked for.A possible solution is the formation of a chemical bond by reacting afunctionalized metallocene and a partly dehydrated silica. In patents EP293815 and DE 3718888 it is described a method for the preparation of asupported catalyst wherein the chemical bond between the support and themetallocene is obtained by reacting an alkoxysilane group united to themetallocene and an hydroxy group of the support. The synthesis of thiscatalyst is difficult and very low yields are obtained. Furthermore, theactivity in the polymerization of the olefins of the resulting catalystsis rather low.

[0011] Patent DE 3840772 describes the use of metallocenesfunctionialized with vinyl groups united to the cyclopentadienyl ring.Heterogeneous systems are obtained by reacting the double bond withpolysiloxanes in the presence of a fit catalyst. This method presentsthe drawback of needing an additional purification process for removingthis catalyst.

[0012] According to patent EP 628566, it is possible to prepareheterogeneous catalysts by reacting ligands already chemically bonded tothe support first with alkyllithium and then with metal halides MX₄(wherein M is a transition metal and X is a halide). This processproduces catalysts with the metallocene tightly bonded to the support.They are used in olefins polymerization in combination with alumoxanes.Also in this case it is necessary a purification of the catalyst systemto eliminate the residues of the reagents used in its formation.

[0013] EP-A-757053 discloses new metallocenes characterized by thefollowing general formula X_(m)M(L-M²(R¹R²)-A-ZR³ _(o)Hal_(p))_(n),wherein M is a metal of group 4, 5 or 6 of the periodic table, each X isindependently selected from hydrogen, halogen or a C₁-C₄₀carbon-containing rest; m is equal to 1, 2 or 3; n is equal to 1 or 2;each L is independently a n ligand, which coordinates to the centralatom M; each M² is independently selected from silicon, germanium ortin); R¹ is a C₁-C₂₀ carbon-containing group; R² is a C₁-C₂₀carbon-containing group or a n ligand, whichl coordinates to the centralatom M; each A is independently a divalent C₁-C₄₀ carbon-containingrest; each Z is independently selected from boron, silicon, germanium ortin; each R³ is independently selected from hydrogen or a C₁-C₂₀carbon-containing rest; o is equal to 0, 1 or 2; each Hal isindependently selected from a halogen atom; p is equal to 1, 2 or 3.

[0014] These compounds are characterized by the presence of ahydrocarbon bridge connecting two silicon, germanium or tin atoms towhom the halogen atom is connected. This characteristic makes themespecially suitable in the preparation of supported catalysts.

[0015] An object of the present invention is to provide new catalystcomponent comprising a bridged metallocene having a Si—Cl functionalgroup bonded to bridge. These compounds can be supported on silica.

DESCRIPTION OF THE INVENTION

[0016] In this invention it is described organo metallic compounds oftransition metals of groups 3, 4, 5 or 6 of the periodic table of themetallocene-type. Besides, the compounds of the present invention arecharacterized in that they have at least one link or bridge between thecyclopentadienyl type unities. The bridge is characterized in that itshows at least one functionality, either included in the bridge orbonded to it, this being a Si—Y, Ge—Y or Sn—Y-type unity, preferablySi—Y, Y being halogen; preferably Y is chlorine or bromine.

[0017] In the present invention it is described the synthesis of thesemetallocenes as well as methods for supporting these compounds ontosolids.

[0018] The invention refers in general to metallocenes represented bythe following formula (Formula I)

[0019] wherein:

[0020] Y is halogen;

[0021] M is a transition metal of groups 3-6 of the periodic table;

[0022] each L is selected from a cyclopentadienyl-type unity, includingindenyl or fluorenyl, substituted or not and the substituents beingequal or different, united to M through a π bonlti; Z is a group thatforms a union bridge between the two unities L, which can have between 0and 20 carbon atoms and between 0 and 5 oxygen, sulfur, nitrogen,phosphorus, silicon, germanium, tin or boron atoms; E is a spacer groupthat unites Z and Y and can have between 0 and 20 carbon atoms andbetween 0 and 5 oxygen, sulfur, nitrogen, phosphorus, silicon,germanium, tin or boron atoms. It is characterized for having in itsskeleton at least one silicon, germanium or tin atom, which thesubstituent Y is united to;

[0023] o is a number of value 0 or 1;

[0024] k is a number of value 1, 2 or 3;

[0025] m is a number equal to or highler than 2 and coinciding with theoxidation state of the transition metal;

[0026] j is a number of value 0 or 1 with the condition that its valueis 1 at least once; when j is 1 and o is 0, Z is characterized by havingat least one silicon, germanium or tin atom which Y is directly unitedto;

[0027] with the proviso that the conipounid does not have generalfornula

X_(m)M¹(L′-M²(R¹R²)-A′Z′R³ _(o)Hal_(p))_(n),

[0028] wherein M′ is a metal of group 4, 5 or 6 of the periodic table,each X is independently selected from hydrogen, halogen or a C₁-C₄₀carbon-containing rest; m′ is equal to 1, 2 or 3; n′ is equal to 1 or 2;each L′ is independently a n ligand, which coordinates to the centralatom M¹; each M² is independently selected from silicon, germanium ortin; R¹ is a C₁-C₂₀ carbon-containing group; R² is a C₁-C₂₀carbon-containing group or a n ligand, which coordinates to the centralatom M¹; each A′ is independently a divalent C₁-C₄₀ carbon-containingrest; each Z′ is independently selected from boron, silicon, germaniumor tin; each R³ is independently selected from hydrogen or a C₁-C₂₀carbon-containing rest; o′ is equal to 0, 1 or 2; each Hal isindependently selected from a halogen atom; p′ is equal to 1, 2 or 3.

[0029] The invention preferably refers to metallocenes represented bythe following formula (formula II):

[0030] wherein:

[0031] Y is halogen;

[0032] M is a transition metal of groups 3, 4, 5 or 6 of the periodictable;

[0033] each L is selected from a cyclopentadieniyl-type unity, includingindenyl or fluorenyl, substituted or not and the substituents beingequal or different, united to M through a π bond;

[0034] Q is an element of group 13, 14 or 15;

[0035] E is a spacer group that unites Q and Y and can have between 0and 20 carbon atoms and between 0 and 5 oxygen, sulfur, nitrogen,phosphorus, silicon, germanium, tin or boron atoms and it ischaracterized by having in its skeleton at least one silicon, germaniumor tin atom, which the substituent Y is united to;

[0036] R is selected from the group comprising: hydrogen, halogen,halocarbon, substituted halocarbon, C₁-C₂₀ alkyl, C₁-C₂₀ alkenyl, C₆-C₂₀aryl, C₇-C₄₀ alkylaryl, C₇-C₄, arylalkyl, C₈-C₂₀ arylalkenyl, alkoxy,siloxy and combinations thereof; A, equal to or different from eachother, is a bridge group between unities L aud Q constituted either byonly one divalent atom of group 16, preferably —O—, or by a trivalentmonosubstituted element of group 15, preferably >N—R, R being definedabove, or a tetravalent disubstituted element of group 14, preferably>C(R)₂ or >Si(R)₂, R being defined above, or by a chain of 2 or moreatoms substituted or not, this chain being preferably of type —C—C—,—C—Si—, —Si—Si—, —Si—O—, —C—O, —C—N—, —C—C—C, —C—Si—C—, —Si—O—Si—;

[0037] o is a number of value 0 or

[0038] k is a number of value 1, 2 or 3;

[0039] m is a number equal to or higher than 2 and coinciding with theoxidation state of the transition metal;

[0040] p, n, 1 are numbers of value 0 or 1.

[0041] j is a number of value 0 or 1 with the condition that its valueis 1 at least once; when j is 1 and o is 0, Q is a silicon, germaniun ortin atom;

[0042] with the proviso that the compound does not have general formula

X_(m)—M¹(L′—M²(R¹R²)—A′—Z′R³ _(o)—Hal₋—)_(n)—,

[0043] wherein M¹ is a metal of group 4, 5 or 6 of the periodic table,each X is independently selected from hydrogen, halogen or a C₁-C₄₀carbon-containing rest; m′ is equal to 1, 2 or 3; n′ is equal to 0 or 2;each L′ is independently a n ligand, which coordinates to the centralatom M¹; each M² is independently selected from silicon, germanium ortin; R¹ is a C₁-C₂₀ carbon-containing group; R² is a C₁-C₂,carbon-containing group or a π ligand, which coordinates to the centralatom M¹; each A′ is independently a divalent C₁-C₄₀ carbon-containingrest; each Z′ is independently selected from boron, silicon, germaniumor tin; each R³ is independently selected fromi hydrogen or a C₁-C₂₀carbon-containing rest; o′ is equal to 0, 1 or 2; each Hal isindependently selected from a halogen atom; p′ is equal to 1, 2 or 3.

[0044] In the most preferred embodiment the invention refers tometallocenes having the following general formulas (III) and (IV)

[0045] herein:

[0046] L, M, m, Y, E, R, I, n have already been defined; C is a carbonatom; T is selected from: silicon, germanium or tin.

[0047] What follows are descriptive and non-limiting examples of thestructural formulas of some metallocene compounds according to thepresent invention:

[0048] In these formulas the following symbols have been used:

[0049] Y, R and M: above defined

[0050] Cp: cyclopentadienyl or substituted cyclopentadienyl ring, alsoincluding in this definition substituted or not indenyl rings andsubstituted or not fluorenyl rings, Cp being able to represent in thesame formula equal or different rings.

[0051] The synthesis of the functionalized metallocenes object of thepresent invention can be obtained according to the general methodrepresented in the following scheme.

[0052] being:

[0053] Y, Z, L, E, M, j, m and o defined above;

[0054] S: leaving group united to the cyclopentadienyl ring, preferablyconstituted by a unity T(R⁴)₃, T being silicon, germanium or tin and Ris C₁-C₂₀ alkyl.

[0055] S represents preferably groups Si(CII₃)₃ and Sn(CII₃)₃. In caserepresented by this scheme, S can represent unities equal or different;in general, the union L—S can represent an ionic, s or π bond or acombination thereof.

[0056] The union L—M always represents a bond with a high π character.

[0057] Preferred compounds of general formula III can be obtainedaccording to the following scheme:

[0058] The synthesis of functionalized metallocenes having a carbonbridge as depicted in formula IV could be achieved following the generalprocedure described in this document starting from a suitable ligand:

[0059] In order to achieve a suitable functionialized ligand, anolefinically unsaturatcd precursor having the unsaturation within unit Ein the formula could be used. Reacting this precursor underhydrosilylation, hydrogermanilation or hydrostannilation conditions thesuitable functional group (Si—Y, Ge—Y or Sn—Y) could be obtained.

[0060] Alternatively, a functionalized metallocene according to formulaIV could be obtained from a metallocene already having an olefinicunsaturation as part of unit E.

[0061] Metallocenes of this type are known in the current literature,for example EP 685495 (Phillips). The functionalization of themetallocene could be achieved again by reacting it underhydrosilylation, hydrogermanilation or hydrostannilation conditions toattach the suitable functional group (Si—Y, Ge—Y or Sn—Y).

[0062] In order to illustrate the different approaches towards thesynthesis, the followilng scheme of a compound having the structureCl₃SiCH₂CH₂CH₂CH₂C(CH₃)Cp₂ZrCl₂ is shown. All the reactive steps shownin this scheme (represented by an arrow) can be of common knowledge fora person skilled in the art of metallocene synthesis and can be obtainedby employing reagents different from those shown in the scheme.

[0063] The procedure employed for step (a) can be learned, for example,from Stone et al. In J. Org. Chem. 1984, 49, 1849. The procedure of step(b) call be learned, for example, from J. Organomet. Chem., 1992, 435,299, or J. Chem. Soc., Dalton Trans. 1994, 657 or EP 685495. Theprocedure for step (c) can be learned from U.S. Pat. No. 5,191,132. Step(d) is the obtaining of the dianion and could be achieved with manydifferent reagents (e.g. Li, Na, K, BuLi, BuMgBr, etc.), here BuLi isshown in order to illustrate one of the most popular reactants employed.Step (e) is also of very common use in the synthesis of metallocenes,see again, for example, J. Organomet. Chem., 1992, 435, 299, or J. Chem.Soc., Dalton Trans. 1994, 657 or EP 685695. Procedures for steps (I),(g) or (j) can be learned from the present document but also fromOrganometallics 1995, 14, 177 or Angew. Chem. Int. Ed. Engl., 1994, 33,1479. Hydrosilylation [steps (h) and (i)] can also be achieved withdifferent reagents, being H₂PtCl₆·6H₂O one of the most commonly employed(see for example Adv. Organomet. Chem. 1979, 17, 407 or J. FluorineChem. 1994, 68, 71 or EP 628566).

[0064] These processes for the synthesis of metallocenes withfunctionalized bridge can be done in the presence of solvent or not. Incase a solvent is used, this can be preferably an aliphatic hydrocarbon,an aromatic hydrocarbon, or mono or polyhalogen containing derivativestherefrom. A mixture of two or more solvents can be used too.

[0065] These processes for the synthesis of metallocenes withfunctionalized bridge can be done in a temperature range between −20 and300° C., preferably between 0 and 200° C., or at the reflux temperatureof the used solvent system.

[0066] These processes for the synthesis of metallocenes withfunctionalized bridge can be done with or without protection from light.Another object of the present invention is to provide new supportedcatalyst components showing a good productivity and producingpolyolefins characterized by a good morphology.

[0067] The supported catalyst component comprising an inorganic supportand a metallocene described in the present invention can be prepared byadding the reagents to a fit inert solvent. Examples of useful solventsare ethers such as tetrahydrofurane (THF), aromatic hydrocarbons, suchas toluene and aliphatic hydrocarbons such as heptane or hexane.

[0068] The inorganic support according to the present invention containshydroxyl groups. Illustrative, but not limiting, examples of supportsuseful in the field of the present invention are the following:silicates, carbonates, phosphates, clays, metaloxides and mixturesthereof. More preferably: silica, alumina, silica-alumina, silicatitanates, silica vanadates, silica chromates, aluminium phosphates,phosphated silica and possible mixtures thereof.

[0069] The surface area of the inorganic support is preferably 10-1000m²/g, more preferably 150-650 m²/g. The pore volume is preferably0.2-4.0 cm³/g, more preferably 0.6-2.7 cm³/g. The average particle sizeis preferably 1-1000 microns, more preferably 5-100 microns.

[0070] The water contained in the support can be optionally removedbefore reacting the support with the metallocene. The dehydrationprocess can be performed by heating the support in an oven in inertatmosphere at a temperature between 120° C. and 1000° C. (preferablybetween 200 and 800° C.). The amount of hydroxyl groups on the supportcan be measured in several ways, for example by titration withn-butylmagnesium chloride or triethylaluminium.

[0071] The concentration of hydroxy-groups depends on the dehydrationtemperature and on the support used. In case silica is used, it can varyfrom 0,1 to 5 mmol OH/g of silica, preferably 0.3 to 3 mmol OH/g ofsilica or from 0,1 to 7 groups OH/nm², preferably 0.5 to 5 groupsOH/nm². Once dehydrated, the support has to be protected fromenvironmental humidity, for example by storing it under inert atmosphere(nitrogen or argon).

[0072] The inorganic support is used as such or it can be previouslymodified through reaction of the hydroxy-groups with compounds offormula V:

[0073] being:

[0074] R: atom of hydrogen, halogen, halocarbon, substituted halocarbon,C₁₋₂₀ alkyl, C₂₋₂₀ alkenyl, C₆₋₂₀ aryl, C₇₋₄₀ alkylaryl, C₇₋₄₀arylalkyl, C₈₋₂₀ arylalkenyl, alkoxy, siloxy and combinations thereof

[0075] X: halogen or group OR⁴ wherein R⁴ has the same meaning givenabove

[0076] P: NH₂, NHR, SH, OH or PHR

[0077] v+z+w=3, v being different from 0

[0078] t and u are comprised between 0 and 10.

[0079] Some examples of compounds of formula III are:

[0080] 3-Mercaptopropyltrimethoxysilane, 3-aminopropyltrimethxysilane,N-Phenylptopyltrimethoxysilane, N-Methylpropyltrimethoxysilane,N-Aminopropyldimethoxymethylsilane, 3-mercaptopropyltrimethoxy-silane.

[0081] Both the functionalized metallocenes object of the presentinvention and their derivatives supported onto inorganic solids can beused in polymerization reactions in conjunction with one or variousco-catalysts. Said co-catalysts are anionic non-coordinative compoundsof alumoxane, modified alumoxane or boron compounds type. In case boronderivatives are used, the supported systems have to be previouslytreated for alkylating the metallocene unities. This alkylation can bedone by using alkylating agents described in literature. Illustrativebut non-limiting examples of co-catalysts are: methylalumoxane (MAO),dimethylaniline tetrakis(pentafluorophenyl)boro ortrispentafluoro-phenylborane.

[0082] The catalyst systems described in the present invention areuseful for the homo and copolymerization of α-olefins, in suspension orin gas phase, as well as in mass polymerization at high temperatures andpressures. The temperature can vary between −60° C. and 300° C.,preferably between 40° C. and 250° C. The pressure can vary between 1and 2000 atmospheres. The polymerization time can vary between 1 secondand 6 hours, according to the process type.

[0083] The process is applicable to all olefins which can be polymerizedby Ziegler-Natta catalysts, it is particularly fit for thehomopolymerization of alpla-olefins from 2 to 20 carbon atoms such asethylene, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene and similar,as well as cyclic monomers and/or dienes. It is also fit for thecopolymerization of ethylene with alpha-olefins different from ethylene,having from 3 to 20 carbon atoms, preferably from 3 to 6 carbon atoms,such as propylene, 1-butene 1-hexene, 4-methyl-1-pentene and similar, aswell as cyclic monomers and/or dienes. The copolymerization of more thantwo alpla-olefins is possible too.

EXAMPLES

[0084] General conditions: The metallocenes synthesis was done in allits steps under the protection of an atmosphere of dry nitrogen, eitherin a dry box or by using the techniques. The used solvents were driedbefore being used according to the methods described in literature. Inthe following examples these abbreviations are used for representing thewritten formulas:

[0085] Cp: cyclopentadienyl radical

[0086] Me: methyl radical

[0087] TMS: trimethylsilyl radical

Examnple 1 Synthesis of((Chloromethylsilandiyl)Bis(Cyclopentadienyl))Zirconium(IV)Dichloride,Cl(Me)SiCp₂ZrClhd 2

[0088] This example is useful for describing a zirconium metallocenewith a functionalized bridge and its synthesis.

[0089] 1.1 Preparation of the dilithium salt ofcyclopentadienyltrimethylsilane, CpTMSLi

[0090] A solution of 40 g (0.29 mol) of cyclopentadienyltrimethylsilanein 300 ml of hexane is added to 200 ml of a 1.25 M solution ofbutyllithium in hexane. During the addition, the reaction mixturetemperature is maintained at 0-5° C. After 3 h at room temperature, theobtained white solid is settled and washed once with 150 ml of hexane.This solid is identified as the desired product. ¹H-NMR(d₈-tetrahydrofurane) 5.95 (pseudo-t, 2H), 5.85 (pseudo-t, 2H), 0.16 (s,911). ¹³C-NMR (d₈-tetrahydrofurane) 112.9, 111.2, 108.09, 2.89.

[0091] 1.2 Preparation of(dichloro(methyl)silyl)(trimethylsilyl)cyclopentadiene, Cl₂(Me)SiCpTMS

[0092] A solution of 30 ml (0.25 mol) of trichloromethylsilane and 250ml of dry hexane is added to a suspension of 0.25 mol of CpTMSLi and 200ml of hexane. Then, the reaction mixture is heated at the refluxtemperature for 5 h. After cooling, the solid is filtered and washedwith 200 ml more of hexane. From the union of the filtered product andthe washing waters, after the elimination of the solvent in vacuum, apale yellow oil that distils at 73-74° C. (2 Torr) is obtained. Theobtained product is mostly the isomer1-(dichloro(methyl)silyl)-1-(trimethylsilyl)cyclopentadiene. Overallyield of steps 1.1 and 1.2: 66.7 g (92%). ¹H-NMR (C₆D₆): 6.61 (m, 2H),6.42 (m, 2H), 0.13 (s, 3H), 0.02 (s, 9H). ¹³C-NMR (C₆D₆): 134.2, 133.6,59.0, 2.5, −1.1.

[0093] 1.3 Preparation ofbis(trimethylsilylcyclopentadienyl)methylchlorosilane, Cl(Me)Si(CpTMS)₂80 ml of a 1 M solution of [CpTMS]MgCl (chloromagnesium derivative oftrimethylsilylcyclopentadienile) in tetrahydrofurane is slowly added toa solution of 20.2 g (0.08 mol) of [Cl₂(Me)SiCpTMS] prepared accordingto 1.2 and 300 ml of hexane. The reaction mixture is maintained understirring for 18 more h at room temperature. The solid is filtered andwashed with hexane (100 ml). The solvent of the filtered product iseliminated and the obtained oil is distilled. The pale yellow fractionthat distils at 110° C. (0.5 Torr) is gathered. Yield: 15.8 g (57%).This fraction consists in a mixture of isomers with formulaCl(Me)Si(CpTMS)₂.

[0094] 1.4 Preparation of((chloromethylsilanediyl)bis(cyclopentadienyl))zirconium(IV)dichloride,Cl(Me)Si(Cp)₂ZrCl₂

[0095] A solution of 10.14 g (0.029 mol) of Cl(Me)Si(CpTMS)₂ and 200 mlof toluene is quickly transferred to 6.69 g (0.029 mol) of ZrCl₄ in acontainer protected from light. This is immediately introduced in a bathat 110° C. and maintained under stirring for 3 h. Then, it is filteredhot and the solution is immediately cooled in a freezer causing thecrystallization of the product, which is gathered through filtration.Yield: 7.7 g (72%). Zr 24.6% (theor.: 24.7%); Cl 28.1% (theor.: 28.8%).¹H-NMR (CDCl₃): 7.04 (m, 2H), 7.00 (mn, 2H), 6.17 (m, 2H), 5.97 (m, 2H),1.12 (s, 3H). ¹³C-NMR (CDCl₃): 129.5, 128.2, 114.5, 113.4, 108.2, −1.7.Mass spectrometry: M⁺ m/z (relative intensity) 373.9 (14%) 372.9 (8%),371.9 (41%), 370.9 (18%), 369.9 (80%), 368.9 (36%), 367.9 (100%), 366.9(30%), 365.9 (71%) [M⁺ calculated for C₁₁H₁₁Cl₃SiZr: 373.9 (13%), 372.9(8%), 371.9 (41%), 370.9 (18%), 369.9 (77%), 368.9 (33%), 367.9 (100%),366.9 (28%), 365.9 (73%)]

Example 2 Synthesis of((Chloromethylsilanediyl)Bis(Cyclopentadienyl))Hafnium(IV)Dichloride,Cl(Me)SiCp₂HfCl₂

[0096] This example describes a hafnium metallocene with functionalizedbridge and its synthesis.

[0097] A solution of 2.15 g (6.1 mmol) of Cl(Me)Si(CpTMS)₂ and 50 ml oftoluene is quickly added to 1.95 g (6.1 mmol) of HfCl₄ in a containerprotected from light. Then, it is soaked in an oil bath previouslyheated at 110° C. It is maintained under stirring in these conditionsfor 2 h, before filtering it hot. The so obtained solution is cooled ina freezer. In this way, it is produced the crystallization of thedesired product, which is identified as Cl(Me)SiCp₂HfCl₂. Yield: 2.1 g(78%). ¹H-NMR (CDCl₃): 6.95 (m, 2H), 6.90 (m, 2H), 6.10 (m, 2H), 5.90(m, 2H), 1.12 (s, 3H). ¹³C-NMR (CDCl₃): 128.2, 126.9, 112.4, 111.4,109.5, −1.7. Masses spectrometry: M⁺ m/z (relative intensity) 460.9(4%), 459.9 (19.5%), 458.9 (19%), 457.9 (65%), 456.9 (50%,), 455.9(100%), 454.9 (60%), 453.9 (55%),452.9 (31%),451.9 (10%) [M⁺ calculatedfor C₁₁H₁₁Cl₃SiHf: 460.9 (4%), 459.9 (21%), 458.9 (19%), 457.9 (70%),456.9 (45%), 455.9 (100%), 454.9 (54%), 453.9 (51%), 452.9 (28%), 451.9(8%)].

Example 3 Impregnation of Cl(Me)SiCp₂ZrCl₂ Onto Silica Calcined at 400°C.

[0098] This example shows an impregnation method of a metallocene with afunctionalized bridge onto an inorganic support.

[0099] The impregnation reaction of the metallocene compoundfunctionalized in the bridge onto the inorganic support is achieved in aglass reactor of a capacity of 250 ml, equipped with a mechanicalstirrer in a thermostatic bath, wherein 2.22 g of silica (previouslycalcined at 400° C., with a concentration of groups OII of 1.55 mmol/g)and 50 ml of dry toluene are added. To this suspension 0.218 g ofCl(Me)SiCp₂ZrCl₂ is added in inert atmosphere and it is heated at 70° C.under constant stirring for 24 hours. The solid is filtered and washedseveral times with dry toluene (5×100 ml) and it is carried to drynessin vacuum. The final solid has a Zr content of 1.87% by weight. Thissupported metallocene catalyst is stable under nitrogen for long periodsof time.

Example 4 Impregnation Of Cl(Me)SiCP₂ZrCl₂ Onto Silica Calcined At 800°C.

[0100] 4.1 Method A

[0101] The mipregnation reaction of the metallocene compoundfunctionalized in the bridge onto an inorganic support is done in aglass reactor of a capacity of 250 ml, equipped with a mechanicalstirrer and a thermostatic bath, wherein 3.4 g of silica (previouslycalcined at 800° C., with a concentration of groups OH of 0.796 mmol/g)and 50 ml of dry toluene are added. To this suspension 1.497 g ofCl(Me)SiCp₂ZrCl₂ in 50 ml of dry toluene is added in inert atmosphereand it is heated at 40° C. under constant stirring for 24 hours. Thesolid is filtered and washed several times with dry toluene (5×100 ml)and it is carried to dryness in vacuum. The final solid has a Zr contentof 1,16% by weight. This supported metallocene catalyst is stable undernitrogen for long periods of time.

[0102] 4.2 Method B

[0103] The impregnation reaction of the metallocene compoundfunctionalized in the bridge onto an inorganic support is done in aglass reactor of a capacity of 250 ml, equipped with a mechanicalstirrer and a thermostatic bath, wherein 3.08 g of silica (previouslycalcined at 800° C., with a concentration of groups OH of 0.796 mmol/g)and 50 ml of dry THF are added. To this suspension 1.35 g ofCl(Me)SiCp₂ZrCl₂ in 50 ml of dry THF is added in inert atmosphere and itis heated at 40° C. under constant stirring for 24 hours. The solid isfiltered and washed several times with dry toluene (5×100 ml) and it iscarried to dryness in vacuum. The final solid hasa Zr content of 0,53%by weight. This supported metallocene catalyst is stable under nitrogenfor long periods of time.

Example 5 Support Of Cl(Me)SiCp₂ZrCl₂ On Functionalized Silica

[0104] In order to illustrate a method for supporting a functionalizedmetallocene with the bond Si—Cl within the bridge ontoamine-functionalized silica, the following two cases are presented:

[0105] 5.1 Method A

[0106] The reaction between the metallocene and the support is carriedout in toluene according to the following procedure: into a three necked250 ml glass reactor with an inert atmosphere of N₂, fitted with anoverhead stirrer, a connection to a vacuum/N₂ line and a septum, firstare added 3,29 g of aminopropil silica gel (with 0,9 mmol/g±0,1 aminogroups, from fluka) which had been previously dried for 7 h at 200° C.under inert atmosphere and, second, a solution prepared with 50 ml ofdried toluene and 0,219 g(0,59 mmol) of Cl(Me)SiCp₂ZrCl₂. The mixture isstirred during 12 h and then the slurry is transferred to a sinteredglass filter funnel closed in order to keep an internal N₂ atmosphere.The slurry is then filtered and washed with 500 ml of dry toluene in thesame filter. The resulting solid is dried at room temperature during 72h under vacuum and transferred inside a nitrogen dry box where it isweighed, resulting in 3,29 g of a light cream coloured solid. Thetoluene rests from the washing were evaporated to dryness leaving behindno residue from the metallocene. The theoretical Zr content is 1,70%(w/w).

[0107] 5.2 Method B

[0108] The same reaction as in Method A is carried out but employing drydichloromethane instead of toluene as the solvent for this example. Theamounts of reactants employed are: 2,75 g of aminopropil silica gel and0,147 (0,4 mmol) of metallocene. The result is 2,53 g of a light creamcoloured solid with a theoretical Zr content of 1,26% (w/w). Again, theliquids from the washing leave behind no residue from the metallocene.

Example 6 Ethylene Polymerization With Heterogeneous Catalyst

[0109] 6.1 This example describes the obtaining of a polyethylene byusing a heterogeneous catalyst system obtained according to Example 3.

[0110] In a flask of 500 ml of capacity, dried and cleaned by a nitrogenflux, equipped with two entries, one provided with a rubber stopper andthe other with a magnetic stirrer, 200 ml of dry heptane are injected ina nitrogen atmosphere. Then, the flask is introduced in a thermostaticbath and the nitrogen atmosphere is substituted by an ethyleneatmosphere through consecutive charges and discharges of ethylene. Then,10.0 mmol of methlylaluminoxane are introduced by using a syringe with ahypodermic needle. The solution being saturated with ethylene and thetemperature being at 40° C., 147 mg of a solid prepared according toexample 3 suspended in heptane are directly injected in the flask. After15 minutes of polymerization 1.16 g of polymer is obtained. The activityof the catalyst system is 155 Kg Pe/mol Zr h atm.

[0111] 6.2 This example describes the obtaining of a polyethyleyne byusing a heterogeneous catalyst system obtained according to Example 4.1

[0112] To a glass reactor of 1.3 liter, previously dried and outgased,600 ml of n-heptane is added. The temperature is raised to 70° C. andthe solvent is stirred at 1200 rpm. When the thermic equilibrium isachieved, the medium is saturated with ethylene at a pressure of 2 bars.Then, 20 ml of a MAO solution in toluene (1.5 M in total aluminium) areadded. The pressure is then raised to 4 bars with more ethylene and 2minutes later 0.157 g of the catalyst of example 4.1 is added. Thesystem is led with ethylene for 15 more minutes and then thepolymerization is stopped by preventing the ethylene flux and adding 20ml of acidified methanol. 3.7 g of polyethylene with a molecular weight(M_(w)) of 169,800 is obtained. The activity of the catalyst system is185 Kg Polymer/mol Zr h atm.

[0113] 6.3 This example describes the obtaining of a polyethylene byusing a heterogeneous catalyst system obtained according to example 4.2.

[0114] In a glass reactor of 1.3 liter, previously dried and outgased,600 ml of n-heptane is added. The temperature is raised to 70° C. andthe solvent is stirred at 1200 rpm. When the thermic equilibrium isachieved, the medium is saturated with ethylene at a pressure of 2 bars.Then 6.7 ml of a MAO solution in toluene (1.5 M in total aluminium) areadded. The pressure is raised to 4 bars with more ethylene and 2 minuteslater 0.172 g of the catalyst of example 4.3 is added. The system is fedwith ethylene for 15 more minutes and then the polymerization is stoppedby preventing the ethylene flux and adding 20 ml of acidified methanol.4.5 g of polyethylene with a molecular weight (M_(w)) of 151,900 isobtained. The activity of the catalyst system is 450 Kg Polymer/mol Zr hatm.

[0115] 6.4 This example describes the obtaining of a copolymer ofethylene and 1-hexene by using a heterogeneous catalyst system with ametallocene functionalized bridge supported onto silica obtainedaccording to example 4.2.

[0116] In a glass reactor of 1.3 liter, previously dried and outgased,600 ml of n-heptane and 10 ml of dry 1-hexene are added. The temperatureis raised to 70° C. and the solvent is stirred at 1200 rpm. When thethermic equilibrium is achieved, the medium is saturated with ethyleneat a pressure of 2 bars. 6.7 ml of a MAO solution in toluene (1.5 M intotal aluminium) is added. The pressure is raised to 4 bars and 2minutes later 0.172 g of the catalyst of example 4.2 is added. Thesystem is fed with ethylene for 15 minutes and then the polymerizationis stopped by preventing the ethylene flux and adding 20 ml of acidifiedmethanol. 4.0 g of a ethylene-1-hexene copolymer with a molecular weight(M_(w)) of 64,000 is obtained. The activity of the system is 400 KgPolymer/mol Zr h atm. The resulting copolymer has 1.5% in molar contentof unities deriving from hexene distributed at random.

Example 7 Copolymerization Of Ethylene And Hexene In Homogeneous Phase

[0117] 7.1 This example describes the obtaining in homogeneous phase ofan ethylene-hexene copolymer by using as catalyst system the metallocenefunctionalized in the bridge Cl(Me)SiCp₂ZrCl₂.

[0118] The polymerization is achieved in 600 ml of heptane in a reactorof 1 liter of capacity. Ethylene and 1-hexene are added to the reactorso that a pressure of 4 bars, the ethylene-hexene molar ratio is 2.0.Then, 5.25 mmol of methylalumoxane in toluene and then 3.5 mmol of themetallocene are added. The reaction temperature is maintained at 70° C.through a heating/cooling system. After 15 minutes 6.5 g of copolymerwith a molecular weight (M_(w)) of 15.548 and a (M_(w)/M_(n))polydispersity of 2 is obtained. The system activity is 1800 KgPolymer/mol Zr h atm. The resulting copolymer has 2.8% by mol unitiesderiving from hexene distributed at random.

1. A metallocene catalyst component for olefin polymerization comprisinga metallocene compound characterized by the following formula:

wherein: Y is halogen; M is a transition metal of groups 3-6 of theperiodic table; each L is independently selected from acyclopentadienyl-type unity, including indenyl or fluorenyl, substitutedor not and the substituents being equal or different, united to Mthrough a π bond; Z is a group that forms a union bridge between the twounities L, which can have between 0 and 20 carbon atoms and between 0and 5 oxygen, sulfur, nitrogen, phosphorus, silicon, germanium, tin orboron atoms; E is a spacer group that unites Z and Y and can havebetween 0 and 20 carbon atoms and between 0 and 5 oxygen, sulfur,nitrogen, phosphorus, silicon, germanium, tin or boron atoms. It ischaracterized for having in its skeleton at least one silicon,germaniun) or tin atom, which the substituent Y is united to; o is anumber of value 0 or 1; k is a nunber ofvalue 1, 2 or 3; m is a numberequal to or higher than 2 and coinciding with the oxidation state of thetransition metal; j is a number of value 0 or 1 with the condition thatits value is 1 at least once; when j is 1 and o is 0, Z is characterizedby having at least one silicon, germanium or tin atom which Y isdirectly united to; with the proviso that the compound does not havegeneral formula X_(m)-M¹(L′-M²(R¹R²)-A′-Z′R³ _(o)-Hal_(p)-)_(n), whereinM¹ is a metal of group 4, 5 or 6 of the periodic table, each X isindependently selected from hydrogen, halogen or a C₁-C₄₀carbon-containing rest; m′ is equal to 1, 2 or 3; n′ is equal to 1 or 2;each L′ is independently a n ligand, which coordinates to the centralatom M¹; each M² is independently selected from silicon, germanium ortin; R¹ is a C₁-C₂₀ carbon-containing group; R² is a C₁-C₂₀carbon-containing group or a π ligand, which coordinates to the centralatom M¹; each A′ is independently a divalent C₁-C₄₀ carbon-containingrest; each Z′ is independently selected from boron, silicon, germaniumor tin; each R³ is independently selected from hydrogen or a C₁-C₂₀carbon-containing rest; o′ is equal to 0, 1 or 2; each Hal isindependently selected from a halogen atom; p′ is equal to 1, 2 or
 3. 2.A catalyst component according to claim 1, characterized in that themetallocene compound has formula:

wherein: Y is halogen; M is a transition metal of groups 3, 4, 5 or 6 ofthe periodic table; each L is independently selected from acyclopentadienyl-type unity, including indenyl or fluorenyl, substitutedor not and the substituents being equal or different, united to Mthrough a π bond; Q is an element of group 13, 14 or 15; E is a spacergroup that unites Q and Y and can have between 0 and 20 carbon atoms andbetween 0 and 5 oxygen, sulfur, nitrogen, phosphorus, silicon,germanium, tin or boron atoms and it is characterized by having in itsskeleton at least one silicon, germanium or tin atom, which thesubstituent Y is united to; R is an atom of hydrogen, halogen,halocarbon, substituted halocarbon, C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₆-C₂₀aryl, C₇-C₄₀ alkylaryl, C₇-C₄₀ arylalkyl, C₈-C₂₀ arylalkenyl, alkoxy,siloxy and combinations thereof; A, equal to or different from eachother, is a bridge group between unities L and Q constituted either byonly one divalent atom of gorup 16, preferably —O—, or by a trivalentmonosubstituted element of group 15, preferably >N—R, R being defineabove, or a tetravalent disubstituted element of group 14, preferably>C(R)₂ or >Si(R)₂, R being define above, or by a chain of 2 or moreatoms substituted or not, this chain being preferably of type —C—C—,—C—Si—, —Si—Si—, —Si—O—, —C—O—, —C—N—, —C—C—C, —C—Si—C—, —si—O—Si—; o isa number of value 0 or 1; k is a number of value 1, 2 or 3; m is anumber equal to or higher than 2 and coinciding with the oxidation stateof the transition metal; p, n, l are numbers of value 0 or 1, j is anumber of value 0 or 1 with the condition that its value is 1 at leastonce; when J is 1 and o is 0, Q is a silicon, germanium or tin atom;with the proviso that the compound does not have general formulaX_(m)-M¹(L′-M²(R¹R²)-A′-Z′R³ _(o)-Hal_(p)-)_(n), wherein M¹ is a metalof group 4, 5 or 6 of the periodic table, each X is independentlyselected from hydrogen, halogen or a C₁-C₄₀ carbon-containing rest; m′is equal to 1, 2 or 3; n′ is equal to 1 or 2; each L′ is independently aπ ligand, which coordinates to the central atom M¹; each M² isindependently selected from silicon, germanium or tin; R¹ is a C₁-C₂₀carbon-containing group; R² is a C₁-C₂₀ carbon-containing group or a πligand, which coordinates to the central atom M¹; each A′ isindependently a divalent C₁-C₄₀ carbon-containing rest; each Z′ isindependently selected from boron, silicon, germanium or tin; each R³ isindependently selected from hydrogen or a C₁-C₂₀ carbon-containing rest;o′ is equal to 0, 1 or 2; each Hal is independently selected from ahalogen atom; p′ is equal to 1, 2 or
 3. 3. A catalyst componentaccording to claims 1-2, characterized in that the metallocene compoundhas formula:

Wherein: L, M, m, Y, R, l, n and A have already been defined; T isselected from: silicon, germanium or tin.
 4. A catalyst componentaccording to claims 1-2, characterized in that the metallocene compoundhas formula:

wherein: L, M, m, Y, R, E, l, n and A have already been defined; T isselected from: silicon, germanium or tin.
 5. A heterogeneous catalystcomponent for the polymerization of olefins obtained from an inorganicsolid that contains hydroxy groups and a catalyst component according toclaims 1-4.
 6. A heterogeneous catalyst component for the polymerizationof olefins according to claim 5 consisting of: an inorganic solid thatcontains hydroxy groups and that has been previously modified throughreaction with a compound of formula:

being: R: atom of hydrogen, halogen, halocarbon, substituted halocarbon,C₁₋₂₀ alkyl, C₂₋₂₀ alkenyl, C₆₋₂₀ aryl, C₇₋₄₀ alkylaryl, C₇₋₄₀arylalkyl, C₈₋₂₀ arylalkenyl, alkoxy, siloxy and combinations thereof;X: halogen or group OR⁴ wherein R⁴ has the same meaning given above; P:NH₂, NHR, SH, OH or PHR; v+z+w=3, v being different from 0; t and u arecomprised between 0 and 10; and a catalyst component according to claims1-4.
 7. A heterogeneous catalyst component for the polymerization ofolefins according to claims 5-6 characterized in that the inorganicsolid is selected from the group comprising: silica, silicates,carbonates, phosphates, clays, metal oxides and mixtures thereof.
 8. Acatalyst system comprising: a catalyst component according to claims 1-7in combination with a cocatalyst selected from the group comprising:non-coordinatinig compounds of alumoxane-type, modified alumoxane-type,boron compounds and combinations thereof.
 9. A catalyst system accordingto claim 8 characterized in that the cocatalyst is selected from thegroup comprising: methylalumoxane, dimethylanilinetetrakis(pentafluorophenyl)boron or trispentafluorophenylborane.
 10. Aprocess for the preparation of the heterogeneous catalyst componentcharacterized in that the compound of claims 1-4 and the inorganicsupport are put in contact by using tetrahydrofurane as solvent.
 11. Aprocess for the polymerization of alpha-olefins, optionally incombination with a cyclic olefin and/or a diene, characterized by thepresence of a catalyst component according to claims 1-7.
 12. A processaccording to claim 11 characterized in that the monomers are selectedfrom the group comprising: ethylene, propene, 1-butene, 1-hexene,4-methyl-1-pentene, 4-octene and mixtures thereof.
 13. A processaccording to claim 11-12 for the copolymerization of ethylene incombination with a comonomer selected from the group comprising:propene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, cyclicolefins and mixtures thereof.